% \( ... \)
\((a, b)=(1, 2)\)  % one space between the comma and the following variable
\((a + b) * c = d(a, b)\)  % no space between parentheses and variables
% $ ... $
$(a + b) * c = d(a, b)$    % no space between parentheses and variables
$a = 1$  % one space before and one space after general binary operators
% \[ ... \]
\[(a + b) * c = d\]  % no space between parentheses and variables
\[a + b \times c = d\]  % \times is also an operator 
\[(a + b) * c = d(a, b)\]  % no space between parentheses and variables
% Suppose if I want to have line break after = operator
\begin{equation}
	a^2 + b^2 = c^2
\end{equation}
